Pip's had some creaking/popping sound from his right front shoulder/leg (maybe neck) area. I can't really pin down the location, but it sounds like my old joints do. He has had no limping, acts and moves normally, and the only other symptom is he has yelped a time or two when someone has touched him in the area. We were at the vets 4/27 (this started about 1 week prior) and the vet didn't find anything unusual, but didn't x-ray or anything since he has not been limping or having difficulty/reluctance walking or running. This started after a yelp during play last month and I think he hurt something, but don't know what or if it is severe. I'm wondering (worrying, maybe needlessly?) if I should take him back to the vet and what in the world could be causing this. Any thoughts would be appreciated!
EDIT: BTW it's not "creaking" as often as it was when we were at the vets, but he did yelp last night when a neighbor let him climb on her lap and tried to pet him there...which makes me wonder if it's maybe his neck.